# How do you prove #cos ((2pi)/3)#?

Let's convert to degrees, which are usually easier to work with.

#= 120 degrees.

Calculating we get a reference angle of 60 degrees. We must now apply our knowledge of the special triangles to continue.

Feel free to ask anything more either on my Socratic dashboard or on the main questions page. I understand that this might at first seem like a long and complicated process.

Practice exercises

Good luck!

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When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

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